Methods for co-producing hydrocarbon products and ammonia

Abstract

A method of a hydrocarbon product and ammonia comprises introducing C2H6 to a positive electrode of an electrochemical cell comprising the positive electrode, a negative electrode, and a proton-conducting membrane between the positive electrode and the negative electrode. The proton-conducting membrane comprising an electrolyte material having an ionic conductivity greater than or equal to about 10−2 S/cm at one or more temperatures within a range of from about 150° C. to about 600° C. N2 is introduced to the negative electrode of the electrochemical cell. A potential difference is applied between the positive electrode and the negative electrode of the electrochemical cell. A system for co-producing higher hydrocarbons and NH3, and an electrochemical cell are also described.

1 . A system for co-producing hydrocarbon products and NH 3 , comprising:
 a source of C 2 H 6 ;   a source of N 2 ; and   an electrochemical apparatus in fluid communication with the source of C 2 H 6  and the source of N 2 , and comprising:
 a housing structure configured and positioned to receive a C 2 H 6  stream from the source of C 2 H 6  and to receive a N 2  stream from the source of N 2 ; and 
 an electrochemical cell within an internal chamber of the housing structure, and comprising:
 a positive electrode comprising a catalyst material formulated to accelerate reaction rates to produce C 2 H 4 , H + , and e −  from C 2 H 6 , and to accelerate reaction rates to synthesize at least one hydrocarbon product from the produced C 2 H 4 ; 
 a negative electrode comprising another catalyst material formulated to accelerate reaction rates to produce NH 3  from N 2 , H + , and e − ; and 
 a proton-conducting membrane between the positive electrode and the negative electrode and comprising an electrolyte material having an ionic conductivity greater than or equal to about 10 −2  S/cm at one or more temperatures within a range of from about 150° C. to about 600° C. 
 
   
     
     
         2 . The system of  claim 1 , wherein the electrolyte material of the proton-conducting membrane is selected from the group consisting of:
 a perovskite material having a H +  conductivity greater than about 10 −2  S/cm at one or more temperatures within a range of from about 400° C. to about 600° C.;   a solid acid material having a H +  conductivity greater than or equal to about 10 −2  S/cm at one or more temperatures within a range of from about 200° C. to about 400° C.; and   a polybenzimidazole (PBI) material having a H +  conductivity greater than or equal to about 10 −2  S/cm at one or more temperatures within a range of from about 150° C. to about 200° C.   
     
     
         3 . The system of  claim 1 , wherein:
 the proton-conducting membrane comprises a yttrium- and ytterbium-doped barium-zirconate-cerate (BZBYYb);   the catalyst material of the positive electrode comprises one or more of Ni—BZCYYb and NiAu—BZCYYb; and   the another catalyst material of the negative electrode comprises one or more of Ru—BZCYYb, RuNi—BZCYYb, RuCe—BZCYYb, and RuNiCe—BZCYYb.   
     
     
         4 . The system of  claim 1 , wherein:
 the proton-conducting membrane comprises CsH 2 PO 4 ;   the catalyst material of the positive electrode comprises one or more of Ni and Au; and   the another catalyst material of the negative electrode comprises one or more of elemental Ru and an Ru-containing alloy.   
     
     
         5 . The system of  claim 1 , wherein:
 the proton-conducting membrane comprises H 3 PO 4 -doped polybenzimidazole (PBI);   the catalyst material of the positive electrode comprises one or more of Ni and Au; and   the another catalyst material of the negative electrode comprises one or more of elemental Ru and an Ru-containing alloy.   
     
     
         6 . The system of  claim 1 , further comprising a heating apparatus configured and positioned to heat one or more of the C 2 H 6  stream, the N 2  stream, and at least a portion of the electrochemical apparatus. 
     
     
         7 . An electrochemical cell, comprising:
 a positive electrode comprising a first catalyst material formulated to accelerate C 2 H 6  deprotonation reaction rates to produce C 2 H 4 , H + , and e −  from C 2 H 6 , and to accelerate coupling reaction rates to synthesize at least one hydrocarbon product from the produced C 2 H 4 ;   a negative electrode comprising a second catalyst material formulated to accelerate N 2  protonation reaction rates to produce NH 3  from N 2 , H + , and e; and   a proton-conducting membrane between the positive electrode and the negative electrode and comprising an electrolyte material having an ionic conductivity greater than or equal to about 10 −2  S/cm at one or more temperatures within a range of from about 150° C. to about 600° C.   
     
     
         8 . The electrochemical cell of  claim 7 , wherein the proton-conducting membrane comprises at least one perovskite material having an H +  conductivity greater than or equal to about 10 −2  S/cm at one or more temperatures within a range of from about 350° C. to about 650° C. 
     
     
         9 . The electrochemical cell of  claim 8 , wherein the at least one perovskite material comprises one or more of a yttrium- and ytterbium-doped barium-zirconate-cerate (BZCYYb), a yttrium- and ytterbium-doped barium-strontium-niobate (BSNYYb), a yttrium-doped BaCeO 3 , a yttrium-doped BaZrO 3 , Ba 2 (YSn)O 5.5 , and Ba 3 (CaNb 2 )O 9 . 
     
     
         10 . The electrochemical cell of  claim 8 , wherein:
 the first catalyst material of the positive electrode comprises one or more of a Ni/perovskite cermet and a NiAu/perovskite cermet; and   the second catalyst material of the negative electrode comprises one or more of a Ru/perovskite cermet, an RuNi/perovskite cermet, an RuCe/perovskite cermet, and a RuNiCe/perovskite cermet.   
     
     
         11 . The electrochemical cell of  claim 7 , wherein the proton-conducting membrane comprises at least one solid acid material having an H +  conductivity greater than or equal to about 10 −2  S/cm at one or more temperatures within a range of from about 200° C. to about 400° C. 
     
     
         12 . The electrochemical cell of  claim 11 , wherein the at least one solid acid material comprises CsH 2 PO 4 . 
     
     
         13 . The electrochemical cell of  claim 12 , wherein:
 the first catalyst material of the positive electrode comprises one or more of Ni and Au; and   the second catalyst material of the negative electrode comprises one or more of elemental Ru and an Ru alloy.   
     
     
         14 . The electrochemical cell of  claim 7 , wherein the proton-conducting membrane comprises at least one polybenzimidazole (PBI) material having an H +  conductivity greater than or equal to about 10 −2  S/cm at one or more temperatures within a range of from about 150° C. to about 200° C. 
     
     
         15 . The electrochemical cell of  claim 14 , wherein the PBI material comprises H 3 PO 4 -doped PBI. 
     
     
         16 . The electrochemical cell of  claim 15 , wherein:
 the first catalyst material of the positive electrode comprises one or more of Ni and Au; and   the second catalyst material of the negative electrode comprises one or more of elemental Ru and an Ru alloy.   
     
     
         17 . A system for co-producing hydrocarbon products and NH 3 , comprising:
 a source of C 2 H 6 ;   a source of N 2 ; and   an electrochemical apparatus in fluid communication with the source of C 2 H 6  and the source of N 2 , and comprising:
 a housing structure configured and positioned to receive a C 2 H 6  stream from the source of C 2 H 6  and to receive a N 2  stream from the source of N 2 ; and 
 electrochemical cells within the housing structure, one or more of the electrochemical cells individually comprising:
 a positive electrode comprising a first perovskite material formulated to accelerate reaction rates to produce C 2 H 4 , H + , and e −  from C 2 H 6 , and to accelerate reaction rates to synthesize one or more hydrocarbon products from the produced C 2 H 4 ; 
 a negative electrode comprising a second perovskite material formulated to accelerate reaction rates to produce NH 3  from N 2 , H + , and e; and 
 a proton-conducting membrane between the positive electrode and the negative electrode and comprising a third perovskite material having an H +  conductivity greater than or equal to about 10 −2  S/cm at one or more temperatures within a range of from about 400° C. to about 600° C. 
 
   
     
     
         18 . The system of  claim 17 , wherein the positive electrode comprises one or more of a Ni-doped yttrium- and ytterbium-doped barium-zirconate-cerate (Ni—BZBYYb), a Ni-doped yttrium- and ytterbium-doped barium-strontium-niobate (Ni—BSNYYb), a Ni-doped BaCeO 3 , a Ni-doped BaZrO 3 , an Ni-doped Ba 2 (YSn)O 5.5 , a Ni-doped Ba 3 (CaNb 2 )O 9 ), a NiAu-doped BZCYYb, a NiAu-doped BSNYYb, a NiAu-doped BaCeO 3 , a NiAu-doped BaZrO 3 , a NiAu-doped Ba 2 (YSn)O 5.5 , and a NiAu-doped Ba 3 (CaNb 2 )O 9 ). 
     
     
         19 . The system of  claim 18 , wherein the negative electrode comprises one or more of Ru-doped yttrium- and ytterbium-doped barium-zirconate-cerate (Ru—BZBYYb) doped with Ru, Ru-doped yttrium- and ytterbium-doped barium-strontium-niobate (Ru—BSNYYb) an Ru-doped PrBa 0.5 Sr 0.5 Co 1.5 Fe 0.5 O 5+δ  (Ru—PBSCF), an Ru-doped PrNi 0.5 Co 0.5 O 3−δ  (Ru—PNC), an Ru-doped Pr 0.5 Ba 0.5 Co x Fe 1−x O 3 , an Ru-doped Pr 0.5 Ba 0.5 FeO 3 , an Ru-doped BaCeO 3 , an Ru-doped BaZrO 3 , an Ru-doped Ba 2 (YSn)O 5.5 , an Ru-doped Ba 3 (CaNb 2 )O 9 ), an RuNi-doped BZCYYb, an RuNi-doped BSNYYb, an RuNi-doped PBSCF, an RuNi-doped PNC, an RuNi-doped Pr 0.5 Ba 0.5 Co x Fe 1−x O 3 , an RuNi-doped Pr 0.5 Ba 0.5 FeO 3 , an RuNi-doped BaCeO 3 , an RuNi-doped BaZrO 3 , an RuNi-doped Ba 2 (YSn)O 5.5 , an RuNi-doped Ba 3 (CaNb 2 )O 9 ), an RuCe-doped BZCYYb, an RuCe-doped BSNYYb, an RuCe-doped PBSCF, an RuCe-doped PNC, an RuCe-doped Pr 0.5 Ba 0.5 Co x Fe 1−x O 3 , an RuCe-doped Pr 0.5 Ba 0.5 FeO 3 , an RuCe-doped BaCeO 3 , an RuCe-doped BaZrO 3 , an RuCe-doped Ba 2 (YSn)O 5.5 , an RuCe-doped Ba 3 (CaNb 2 )O 9 ), an RuNiCe-doped BZCYYb, an RuNiCe-doped BSNYYb, an RuNiCe-doped PBSCF, an RuNiCe-doped PNC, an RuNiCe-doped Pr 0.5 Ba 0.5 Co x Fe 1−x O 3 , an RuNiCe-doped Pr 0.5 Ba 0.5 FeO 3 , an RuNiCe-doped BaCeO 3 , RuNiCe-doped BaZrO 3 , an RuNiCe-doped Ba 2 (YSn)O 5.5 , and an RuNiCe-doped Ba 3 (CaNb 2 )O 9 ). 
     
     
         20 . The system of  claim 19 , wherein the proton-conducting membrane comprises one or more of a yttrium- and ytterbium-doped barium-zirconate-cerate (BZCYYb), a yttrium- and ytterbium-doped barium-strontium-niobate (BSNYYb), a yttrium-doped BaCeO 3 , a yttrium-doped BaZrO 3 , Ba 2 (YSn)O 5.5 , and Ba 3 (CaNb 2 )O 9 .